The present invention relates generally to video receivers, and more particularly to methods and systems for selecting between incompatible video formats in a way that is transparent to the user.
To produce a color video image, the image from the camera is broken down into its component primary colors, namely, red, green, and blue, and then combined and transmitted to a receiver which essentially reverses the operation of the camera to render the image sought to be displayed. To reduce the amount of information that must be transmitted and thereby advantageously conserve transmission bandwidth, older video formats use transmission schemes, including so-called xe2x80x9ccompositexe2x80x9d video and xe2x80x9cS-videoxe2x80x9d, in which only one line (in the case of composite video) or two lines (in the case of S-video) are used to carry the color video signal to the receiver.
Unfortunately, however, while the two above-mentioned formats conserve bandwidth, they do so at the expense of image resolution. Accordingly, a relatively new format, referred to herein as xe2x80x9ccomponent videoxe2x80x9d, has been introduced. In component video, the three primary color images are transmitted along respective lines, thereby increasing the resolution and, hence, quality of the video image that is output by the receiver. Many digital video disk (DVD) players that provide relatively large bandwidth and, thus, that facilitate the use of component video, accordingly employ the component video format.
To accommodate all three of the above-mentioned formats, many modern televisions can accept composite video inputs, S-video inputs, and component video inputs. To select among the inputs, however, a user must manipulate the local or remote control of the television itself to cause a menu of selections to appear on screen, and then the user must select which input is desired to be presented. This can be comparatively cumbersome.
Moreover, many television sets receive their input from an audio video (AV) receiver such as, e.g., the AV receiver associated with a video cassette recorder (VCR). Because many if not most AV receivers are configured only for the composite video and S-video formats and not for component video, however, the component video input to the television cannot be received through the AV receiver. Instead, it must be received as an input that is separate from the AV receiver. As one consequence, multiple remote control sets (e.g., one for the AV receiver and one for the television) are required. As users have discovered, the requirement to use multiple remote control units is annoyingly cumbersome and confusing, and multiplies the likelihood that a remote control unit will be lost or misplaced.
Fortunately, the present invention recognizes that is possible to provide a means for controlling the presentation of incompatible video formats in a way that is transparent to the user, using AV receivers that are not otherwise configured for the component video format. Accordingly, it is an object of the present invention to provide a system and apparatus for controlling the presentation of incompatible video formats in a way that is transparent to the user. Another object of the present invention is to provide a system and apparatus for enabling a user to switch between video channels having incompatible formats using only a single remote control unit. Still another object of the present invention is to provide an AV selection system and apparatus that is easy to use and cost-effective to manufacture.
Other features of the present invention are disclosed or apparent in the section entitled: xe2x80x9cBEST MODE FOR CARRYING OUT THE INVENTION.xe2x80x9d
A video selection system is disclosed for selectively outputting signals to an audio video (AV) output device that includes a video display. The system includes a switch box configured for receiving at least one S-video signal and/or at least one composite video signal, and at least one component video signal, with the component video signal including a synchronization signal. In accordance with the present invention, the switch box selectively outputs, to the AV output device, either the component video signal or one of the S-video and composite video signals, based on the synchronization signal.
In a preferred embodiment the AV receiver provides a sense signal to the switch box, and the sense signal is compared to the synchronization signal to determine which video signal to present on the AV output device. The switch box is disclosed in combination with the AV receiver, which is configured for receiving the S-video input and/or the composite video input and sending these inputs to the switch box.
To establish the sense signal, the switch box sends the synchronization signal from the component video source to a first input port of the AV receiver to establish a trigger signal. When the first input port of the AV receiver is selected, the trigger signal establishes the sense signal that is input to the switch box.
Additionally, the switch box includes a video decoder for receiving one of the S-video signal and/or composite video signal to output a video signal that has been transformed to the component domain. A switch is electrically connected to the video decoder for receiving the transformed video signal therefrom, and the switch also receives the component video signal. When the sense signal from the AV receiver matches the synchronization signal from the component video source, the switch outputs the component video source signal; otherwise, the switch outputs the AV receiver video signal. In either case, the switch operates in the component domain.
To execute the above-described operation, a controller is in the switch box, in communication with the switch, for controlling the switch to establish the switch output. As disclosed in detail below, the controller includes a comparator for comparing the sense signal to the synchronization signal. Also, the controller includes a valid video determiner for causing the S-video signal or composite video signal to be sent to the AV output device when the S-video signal or composite video signal is valid and the sense signal does not match the synchronization signal.
Desirably, a remote control device is associated with the AV receiver. The remote control device is operable to select the first input port of the AV receiver to thereby cause the AV output device to present an image generated by the component video signal.
In another aspect, a method is disclosed for causing a video output device to present an image from a component video source or from a combined S-video and composite video source. The method includes electrically connecting the component video source and the combined S-video and composite video source to the video output device. Also, the method includes establishing an input port of the combined S-video and composite video source to be a trigger port. A synchronization signal is derived from the component video source and sent to the trigger port. Then, an input port of the combined S-video and composite video source, other than the trigger port, can be selected by the user to thereby cause the output device to present an image from the combined S-video and composite video source. Or, the trigger port of the combined S-video and composite video source can be selected by the user to thereby cause the output device to present an image from the component video source.
In still another aspect, a video selection device includes first video input ports including at least one of: one or more composite video input ports, and one or more S-video input ports. The device of the present invention also includes at least one component video input port. Furthermore, the device includes a video decoder that is electrically connected to at least one of the first video input ports, such that the decoder processes a video input into the component domain.
A switch is electrically connected to the video decoder for receiving the output from the decoder, and the switch is also electrically connected to the component video input port. As disclosed in detail below, a controller is electrically connected to one or more of the video input ports and to the switch, and the switch selectively outputs a signal from one of: a first video input port, and the component video input port, in response to the controller.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts.